This invention relates to cameras in general and, in particular, to those for use with a perforated strip of film rolled in a magazine. More particularly, the invention deals with improved means for expediting the loading of such a magazine and the subsequent threading of the film in a camera.
A roll-film camera of the type in question usually requires a troublesome process of magazine loading and film threading. The user first drops the magazine into a magazine chamber at one end of the camera body. Then, pulling the leader of the film out of the magazine, he must insert its end into a slit in a takeup spool rotatably mounted in a spool chamber at the opposite end of the camera body. The user proceeds to engage the film perforations with a feed sprocket or sprockets, while making sure that the spool will properly take up the film. The back cover of the camera body is then closed. The loading operation is completed when the user takes one or more unexposed shots.
Not only is this usual method of magazine loading troublesome and time-consuming, but also it often invites failure of the takeup spool in winding up the film. Recently, therefore, camera makers the world over have suggested a variety of measures for easier, more positive loading of the roll-film magazine in the camera.
Typical of such recent proposals is what is tradenamed "Konireel", mounted on some Konica cameras. The Konireel is, in essence, a takeup spool having two tubes nested one within the other. The outer tube has a plurality of slots extending parallel to the spool axis. The film leader is inserted into one of these slots. On actuation of the windup lever, the inner tube revolves to engage the film leader between itself and the outer tube.
Another conventional measure is known as "Canon Quick Loading (QL) System" featuring three friction members pivotally mounted on the takeup spool and sprung away therefrom. Another feature of the QL system is a film guide mounted on the camera body for pivotal motion with its back cover. As the windup lever is turned, the film leader placed over the takeup spool is wrapped around the same by advancing in frictional contact with the friction members and in sliding contact with the film guide and with the arcuate surface bounding the spool chamber.
These and similar conventional devices are in common subject to the objection that the takeup spool and associated film guiding or winding means are complex in construction. The result is the higher production costs of cameras incorporating such devices. Further, the user of a conventional device tends to worry that the takeup spool may not be winding up the film, it being rather difficult for him to visually ascertain the wrapping of the film around the spool.
Another difficulty heretofore encountered in loading the magazine arises from the unavoidable curling of the film unrolled therefrom. When the film leader is threaded into engagement with the takeup spool, the curled film tends to direct the tangentially projecting mouth of the magazine obliquely upward. Thus the film will not easily engage with the feed sprocket or sprockets and, in some instances, may become disengaged from the takeup spool or may not be properly rolled thereon. Further, upon closure of the back cover, the curled film may become slack between magazine and spool, or its leading end may slip out of engagement with the spool. Particularly with cameras equipped for a self-winding function, the user may not notice such a failure in the film moving mechanism.